Enhanced Data GSM Environment (EDGE) is a wireless Third Generation (3G) technology that allows an increase in data transmission rate and improves data transmission reliability. EDGE can be used for any packet switched application such as an Internet connection. EDGE is implemented as an add-on enhancement to 2G and 2.5G Global System for Mobile Communications (GSM) and General Packet Radio Service (GPRS) networks, making it easier for existing GSM carriers to upgrade to it.
In the continuing evolution of the 3G standard, Wideband Code Division Multiple Access (WCDMA) has been developed. More technically, WCDMA is a wideband spread-spectrum mobile air interface that utilizes the direct sequence Code Division Multiple Access (CDMA) signaling method to achieve higher speeds and support more users compared to the implementation of time division multiplexing (TDMA) used by 2G GSM networks. WCDMA has been developed into a complete set of specifications, a detailed protocol that defines how a mobile phone communicates with the tower, how signals are modulated, how datagrams are structured, and system interfaces are specified allowing free competition on technology elements.
With Enhanced Data GSM Environment (EDGE) Continued Evolution work in the Third Generation Partnership Project (3GPP) one aim is to improve the seamless workability between WCDMA and EDGE. One main target is reduced latency, which is very beneficial for applications like Voice Over Internet Protocol (VoIP), Push-to-talk over cellular (PoC) and Mobile TV and Gaming.
In a conventional system, the mobile station (MS) is capable of indicating to the radio access network (RAN) that it can handle more than 1 time slot (TS) in the uplink, however the RAN is restricted by the current 3GPP standard to assigning only 1TS for an uplink TBF in one direction, and when the RAN finds out that transmission in the other direction is necessary, assigns another TBF in the other direction. Therefore, once the RAN finds out about the MS capabilities, either during the second phase of a two phase access or by querying the Serving GPRS Support Node (SGSN) for this information for the case of a one phase access. The result of this is a slower ramp-up in throughput and an increased delay. This restriction increases the initial delay for services like VoIP and Push-to-talk (PoC) and Mobile TV and Gaming. Since almost all transactions are bi-directional, this sequential approach adds unnecessary delays and protocol overhead.
Any discussion of documents, acts or knowledge in this specification is included to explain the context of the invention. It should not be taken as an admission that any of the material forms part of the prior art base or the common general knowledge in the relevant art.